So in all of the discussions of the status of the LHC, there has been little change to the new plan that emerged a few weeks ago: the machine will run at half-energy through most of 2010. The two general purpose experiments, Atlas and CMS, will just have to be patient. But at the end of an LHC status talk, the Atlas team’s Mel Shochet, of the University of Chicago, had a question: how will the LHC fix the problem with the splices for good? Mel had heard a rumor that the LHC would be shut down for quite a while as the welded splices were replaced with clamps — a simpler technology used effectively at Fermilab’s Tevatron.
Would LHC engineers do the clamping over the course of several planned shutdowns each winter? If so, that could put the time when the LHC could operate at full 14 TeV energies way off in the future. On the other hand, shutting down to do all the clamping at once would mean that the LHC would have to be shut down for a long time — maybe even a year — which presents a problem of its own.
In the hallways, I found Rolf-Dieter Heuer, the Gandalf-like director general of CERN, and asked him for his sage thoughts. “Clamping hasn’t been decided, but it very well could be an option,” says Heuer, who is having a bit of a homecoming here — he was the research director of DESY for many years. Heuer says the main thing is to get some data to the experiments and give engineers a feel for the machine. Deciding how to fix the bad splices will come later, he said.